The present invention relates to a power brake system for vehicles, in particular, motor vehicles.
The power brake systems currently mounted on internal combustion engine vehicles, in particular, motor vehicles, have a hydraulic brake control cylinder interlocked with a pneumatic cylinder divided into two chambers by an internal membrane. The said two chambers normally communicate with each other, and are provided with complicated valve assemblies activated by the brake pedal and designed to cut off communication between the said two chambers, and to cause one to communicate externally and the other to communicate with an intake manifold on the engine.
Known power brake systems of the aforementioned type are usually highly complex and expensive to manufacture. Furthermore, in the event of breakage of the said membrane, operation of the brake pedal connects the engine lubricating oil circuit directly with the outside atmosphere, on one side, and with the intake manifold on the other.